Sanitized Copy Approved for Release 2011/09/21: CIA-RDP80-00809A000700010230-3 1 CLASSIFICATION coNFIDENTZAL CENTRAL INTELLIGENCE AGENCY REPORT FOREIGN DOCUMENTS OR RADIO BROADCASTS CD NC. COUNTRY USSR SUBJECT Scientific - Electronics, battery receivers HOW PUBLISHED Monthly periodical WHERE DATE PUBLISHED Apr 1951 LANGUAGE I.I. DO C U UEHI CO MTAIMS INIORY ATION AFFECTING THE NATIONAL -ACT IN 1% O! ST HC SNIAND SI. AS AMENTOEO i ITS TRANSYCSSIONEOR ITHEA REY ILATION A UNA OF ITS COTTA Mrs I RANT W NNER S! THIS IDRYHOEIED HIBRSON IS PRO O MI bIT ED BY A. 1PAoDUCT1 RR DATE OF INFORMATION 1951 DATE DIST. /C- Sep -951 NO. OF PAGES 5 SUPPLEMENT TO REPORT NO. THIS IS UNEVALUATED INFORMATION The requirements for a cheap, mass-produced battery radio area v fhe designers of the Tula rece equip- , first rire in A ounications receivereisgappendedi/ rthe Minist~y adiofication of ment for rural Because their price and operating expenees must be kept down. mW1sR. battery receivers are more difficu_t to design than bsecond.class ortevennf? cost class radios in which standard units and pats can of power in a thi^3..?-lass battery receil!er three to urmtimes that atrofianfi rst- class line receiver, it can be readily understood Y odaih economic described in this report, were awarded er i scription to the center, -- -e,- The initial price should no be muc a wired radio center and the operating costs should not exceed the price of a sub- than h y -i ----- equal in quality and volume to that, provided b e +i of local and neighboring stations must be at least T? hAt.trrV or tubes fail, provision should be made for crystal-set operation Maintenance must be very simple. The Tula battery receiver satisfies all these requirements. Circuit In the schematic diagram of the Tula receiver, as seen in he appended figure, two miniature tubes, the 1B1P and 2P1P, are used. The format operates as a grid de- tector and of amplifier the diode section is not used'), while the latter acts as C017, DENTIAL OONFIDENTIA , Sanitized Copy Approved for Release 2011/09/21: CIA-RDP80-00809A000700010230-3 Sanitized Copy Approved for Release 2011/09/21: CIA-RDP80-00809A000700010230-3 1 an output tube and phase-inverter for regeneration. his is the nngum- stn um of tubes capable our of ensuring good tuned circuit, directly connected ber stations with an outdoor antenna. Only one with the antenna, is used. To increase selectivity and amplification, feed- back is provided from the plate circuit of the second tube through the small semivariable capacitor Cl0. This regenerative circuit needs no special feedback coil or supplementary tape on the tuned circuit; hence, the band switch can be greatly simplified. Moreover, this circuit does not permit one to look for a station while rereby ive indirr is oscillating phtraansmission fromrthenreceiver. Thisris,accom- ple l a preventing spurious on of plished, at the threshold of oscillation, by the simultaneous ito tunef impossible oscillations which blanket all incoming signals, making in a station. Thus, the main defect of regeneration, i.e., the possibility of interfer- ence with nearby radios, is eliminated, while its good qualities are retained. The regenerative control consists of a screw-driver adjustment on the back of the cabinet. Uniform amplification at various points of the band is obtained by proper selection of the parameters for the compensation circuits L5-R7 and Rg-C7. . A differential capacitor C9 is connected between the tuned circuit and the control grid of the first tube to regulate the volume. The circuit is tuned by an "al'sifer" [Al-Si-Fe7 core, which passes suc- L and L4, would on one form. The sliding con- cessively through coils ml, L2, tact of the band switch h moves wit the core along the nand thereforee ttap hesfric- the coils going to the chassis are used for switching, tion of the band switch does not cause crackling and noise. The jacks to connect the output transformer the wired radio network are connected in parallel with its pr Y winding. For use as?a crystal receiver, special jacks the aare reeprovidi edatoeconnectgupe~he crystal detector (D in appended figure) Design The main unit is the loud-speaker because its dimensions determine the shape and size of the cabinet. The Tula speaker has aosconCe halfef - times larger than the spagkers in ordinary cheap radi. is increased and its frequency response smoothed because of the more effective reproduction of the medium and low frequencies. The front panel serves both to support the cone and to brace the field coil. In the lower part of the cabinet there is a panel on which the tube sockets, out- put transformer, circuit coils, capacitors, and resistors are arranged. Two very similar cabinet types can be used. The most original part of the receiver is the combination of in one knob on the front panel. When the knob is lifted up, battery, actuates the mechanism which shows that the power is on, and regulates the volume and feedback. Smooth tuning and band-switching are obtained by mov- ing the knob horizontally. CONFIDENTIAL Sanitized Copy Approved for Release 2011/09/21: CIA-RDP80-00809A000700010230-3 Sanitized Copy Approved for Release 2011/09/21: CIA-RDP80-00809A000700010230-3 1 The method of construction is described below. Parallelxtonthe coiltform there is a rectangular metal bar along which a carriage ion control knob) can move. Attached to the carriage there is a flexible cord which passes through the roller intoethera ilyformawheere the movableonalcti ertheore, connected at both ends with ed. s of switch, made in the form of a flexible hemisphere, issfastenedoto thismcarriage. When the carriage is moved, the passes strips which are fastened to the panel and to which the ends of the coil are connected. A metal plate acting as one of the differre t ntial capacitor plateslissattached at the extreme right end of the bar; the p the tuned circuit. When the control knob is raised, the horizontal bar rotates through a certain angle and the movable plate approachhestthefplate*-fastenedr-to the receiver panel and connected to the control grid change in ce2ac.itance between these two plates regulates the volume. Also at the right end of the bar is a system of levers which actuates the supply switch and signal- Flat clamps are placed on the back edge of the paned for connecting the an- tenna and groand, the head,et, and the wired radio line. All the parts are designed for mass production, the great majority being stamped. There are practicaii.y no turned parts or screws The amount of metal and other material used is likewise very small. The total weight of the Tula is 1.6 kg, whereas the B--912 weighs almost 3.5 kg. Supply The supply system was designed to provide maximum life for tubes and bat- teries. Research has shown that miniature low tubes can operatione with a filament current of 45.50 voltage. The life of a tube under these operating conditions is greatly in- creased, and the battery load is lightened. The eh3Sgcells through toi0upplysthe filaments have a capacity of 30 amp- tance. However, if the discharge current is reduced to one half or one third, their capacity will be doubled in operation under intermittent discharge condi- tions. The filaments of the tubes are connected in series. Two series-connected ma, has 3S cells provide anoinitial filament currentdoof150tma ceAfterltheeradio drop been operating for 2 to 2? mo (for 3 to 4 2,2.2.3 v. Thereafter, one half of the 2P1P filament is shorted by a switch and file the receiver has to the need Thaisfitype rhei- also begins went supply ly stat. A BAS-.G--60 battery is used as a plate-voltage Under'intesrmviceittent er, discharge with current less than 3.5 p i.e., at least as long as the filament battery made up of 3S cells under the operating conditions described above. To prevent the tube filaments from burning out through unskillful handling, both the filament and plate batteries are enclosed in one case. To this case is fastened a tube-type socket with jacks, into which the receiver plug is connected. pplateplugvoltagecan the in thus the The Operational tests of this battery unit with the receiver showed that its life exceeded 1,000 hr. X0 INI Fi0FE, HII 1A L Sanitized Copy Approved for Release 2011/09/21: CIA-RDP80-00809A000700010230-3 Sanitized Copy Approved for Release 2011/09/21: CIA-RDP80-00809A000700010230-3 NTIM- -- 'rne lel:Cl--l --.? -r-.---- --- - --- - v and a filament volt. ates with cati_factory 'ro'ume at a plate ,oltage of 30 age of __5 v, One of the advantages of a straight Jtuned rfI amplification circuit is that the supply voltages are not critical. For the supply voltages first mentioned, the sensitivity and volume of the Tula are adequate. If these voltages are raised 50%, that is, up to 4 v' for the filament (three 3S cells) and 80 v for the plates (BAS.80 battery), the electroacoustic characteristics will be greatly improved, while the oper- ating conditions for the tubes remain within their established norms. In this case. however, operating expenses will be somewhat higher. Preliminary calcu- lations indicate that the operating costs of the receiver plus the subscription jTicense7 fee will be considerably less than the subscription fee established for the use of a wired. radio loud..-speaker parameters of the T;,la slits Norms According to Specifications Results of Tests Current consumption from supply source In plate circuits when EP = 60 v ma 4,5 3.43.6 0 In filament circuits when Ef = .} ma 60 5 Frequency band- Medium wave kc 535'-1500 500-1600 4 Long wave kc 150?-410 15 117- Sensitivity at average sound pressure of 1.3 dynes per sq cm at a distance of 1 m my 40 li-37 Manual volume control range db 20 20 Variation of frequency response in fre- quency range of 200-3,500 cps In entire unit db 20 14.15 In loud-speaker db 12-15 Harmonic content with respect to sound pressure 15 4.5-?11 Mean sound pressure of speaker i.n range of 200-2,000 cps for 0.1 va in field bar 2.3 4..4.3 coil Results of Tests Models of the Tula have been tested under normal operating conditions in kolkhozes 150?200 km from Moscow with antennas 15-20 m long, suspended at a height of about 10 m. The volume of reception from all three Moscow stations was more than adequate in small rooms. With more regeneration, satisfactory reception could be obtained from other cities (Leningrad, Minsk). The tests showed the convenience of the control arrangements. In places where just one station could be heard, the receiver operated practically like a push-button radio, since, with faxed tuning, it was only necessary to move the knob up and down for switching on and off and for volume control. A years trial also demonstrated the economical operation of the receiver and the long life of the tubes for the supply voltages mentioned previously. The manufacture of the first series of Tula radios in 1951 and their use under varied conditions will enable listeners and amateurs to make suggestions for improving the operational and acoustic properties of the receiver. It should become the most widely used radio in nonelectrified rural areas. CONFIDENTIAL CIeFIBENT IAI. Sanitized Copy Approved for Release 2011/09/21: CIA-RDP80-00809A000700010230-3 Sanitized Copy Approved for Release 2011/09/21: CIA-RDP80-00809A000700010230-3 1 t. . Figure 1. Schematic Diagram of the Tula Receiver ZI-n this diagram, as in all other diagrams used in the periodical Rio, the following coding of resistors and capacitors is used- C 65 f~ R 800, SOOn, C 3T=3,00or.r~td, c 5.5T=5,5001 fd, c o.3= or d C 4.0=4 , R 40T*40,000n,R 0.2=0.2 M,-4R 2.0=2M". Thus, in the given diagram, Cl = loof""I.f d, 0 / , R2 = 2Mr~, R R, = 1.500.1-, etc . M ,I Sanitized Copy Approved for Release 2011/09/21: CIA-RDP80-00809A000700010230-3

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